Deformable body and combination of such deformable body and a surgical screw element

ABSTRACT

The present invention provides a deformable body (2), wherein the deformable body comprises a force application surface (12) opposite a bone contact surface (52) to be pressed against periosteum of a bone surface (52) of a bone such that the bone contact surface adapts its shape to the shape of the bone surface, wherein the deformable body comprises one or more through-going openings (3) and/or one or more fixation locations (34) arranged to receive a fixation element such as as screw (20), and wherein the deformable body comprises an anaesthetic that is released from or through the bone contact surface. The anaesthetic can be bupivicaine, liposome bupivacaine, lidocaine or levobupivacaine. The anaesthetic can be arranged in one or more compartments (6, 7) which have different release rates. The screw can comprise a detent or rim to mate with the deformable body. A sleeve (80) can be arranged in the opening (3) to receive the screw. A pusher element (81) can push the deformable body from the sleeve into position on the screw shank (21).

The present invention relates to a deformable body and to a combinationof such deformable body and a surgical screw element.

US 2010/031228 discloses a pedicle screw system to be used in spinalfixation systems. In such spinal fixation system, pedicle screws areused to anchor the spinal fixation system in the respective vertebrae ofthe spine of the patient to be treated. The fixation of the spine mayfor example be used in treatment of diseased spines, for example causedby cancerous tissue or fractures being present in the spinal column ofthe patient.

For fixation of the spinal fixation system each of the pedicle screwelements is fixed through a respective pedicle of a vertebra of thepatient. The placement of such pedicle screw element typically causesmuch pain, in particular due to the damage that is caused to theoverlying periosteum of the vertebra as a result of the pedicle screwelement being introduced in the pedicle of the vertebra.

To decrease the high level of pain experienced by the patient, highdoses of analgesics, for example morphine, may be administered to thepatient either through oral, subcutaneous, intramuscular or intravenousroutes. However, in practice, the morphine doses necessary to provide areasonable level of comfort to the patient often lead to relevantside-effects and/or adverse events.

It is an object of the invention to provide an improvement in thetreatment of pain, in particular caused by placement of screw elementsin the skeleton, whereby the periosteum is damaged by the screwelements. It is a further object of the invention to improve thetreatment of pain in surgical procedures in which screw elements areplaced in skeletal structures, for example pedicle screws introducedinto the spine of a patient.

The present invention provides a deformable body as claimed in claim 1.

The deformable body of the present invention is an anaesthetic-carryingbody intended to be pressed with its bone contact surface on theperiosteum of an outer surface of a bone to be treated. By pressing thebone contact surface, also referred to as periosteum contact surface, ofthe deformable body on the periosteum, the deformable body will bedeformed, preferably elastically deformed. As a result, the bone contactsurface of the deformable body will adapt its shape to the shape of theouter bone surface, therewith covering the overlying periosteum of thebone.

In this application, deformable means that the material of thedeformable body is flexible such that its surface shape can adapt to ashape of a surface against which the deformable body is pressed. Thedeformability of the deformable body is selected such that due to thedeformation of the deformable body, the bone contact surface of thedeformable body comes into intimate contact with the outer bone surface,when the deformable body is squeezed.

In practice, the deformability of the deformable body may be similar tothe deformability of a wine gum.

In the deformable body an anaesthetic is provided which is released fromor through the bone contact surface of the deformable body. When thebone contact surface of the deformable body is in intimate contact withthe bone surface directly next to the location where the screw isbrought into the bone, the anaesthetic is provided directly at theorigin of the pain, in particular due to the damaged periosteum,experienced by the patient. This results in an effective pain relief fora patient that is treated. Since the anaesthetic is released directly atthe desired location, less anaesthetic will have effect in tissue in thesurrounding area, i.e. in areas where less pain relief by anaestheticsis desired.

The Young's modulus of the material of the deformable body may be in therange of 1 kPa-1 GPa, for example in the range of 10 kPa-1 GPa. Theyield point of the material of the deformable body may be in the rangeof 10 Pa-20 MPa.

The material of the deformable body may be soft material, for examplesubstantially softer than metals.

The deformable body comprises one or more through-going openings and/orone or more fixation locations, arranged to receive a fixation elementtherethrough. It is of importance that the bone contact surface of thedeformable body is pressed against the bone surface of a bone to betreated. The deformable body may be provided with one or morethrough-going openings to accommodate a fixation element, for example ascrew element, that can be used to fix the deformable body on the boneand/or to press the deformable body against the bone surface. The one ormore through-going openings may also be used to arrange other fixationelements therethrough, such as, when used in combination with, forexample, a plate, a wire or a band.

In an alternative embodiment, the deformable body may comprise one ormore fixation locations that are arranged to receive a fixation elementtherethrough. The one or more fixation location may be grooves orrecesses that allow the fixation element to hold the deformable body ata desired location on a bone surface, and to press the deformable bodyon the bone surface.

In an embodiment, the deformable body may have two recesses at oppositesides of the deformable body, such that a thin part, for example amembrane, remains between the two recesses. This thin part may bepierced by for example a screw element to form a through-going opening.The thin part may also be created by arranging a recess at one side ofthe deformable body.

The administration of the anaesthetic can be modulated to provide adesirable release profile of the anaesthetic over time.

The anaesthetic may be an amino-amide local anesthetic, such aslidocaine, prilocaine, bupivicaine, levobupivacaine, ropivacaine,mepivacaine, lidocaine, dibucaine, etidocaine, or other amino-caine. Theanaesthetic may also comprise a combination of two or more types ofanaesthetics. Preferably, the anaesthetic is bupivicaine, liposomebupivacaine or levobupivacaine, lidocaine, or a combination ofanaesthetics comprising bupivicaine, liposome bupivacaine and/orlevobupivacaine.

It is remarked that U.S. Pat. No. 8,333,791 discloses the use of tiesthat can be coupled on with one or more parts of a medical device afterthe medical device has been implanted in the human body. The medicaldevice is for example a pedicle screw or spinal rod around which the tiemay be provided. The tie has a time-release therapeutic substanceincorporated therein. After the surgical procedure is completed the tiewill release the therapeutic substance when the tie is exposed to an atleast in part aqueous substance.

Further, WO 2009/045743 discloses the use of non-load bearing spinalcomponents comprising a pharmaceutical component in a spinal screwassembly. The non-load bearing spinal component is for example bonescrew cap mounted on the proximal end of a screw element of the spinalscrew assembly. In another embodiment, the non-load bearing spinalcomponent is provided as a rod cover configured to be arranged on aspinal rod of the spinal screw assembly. After implantation, thepharmaceutical component is released from the non-load bearing spinalcomponent according to a desired release profile.

The deformable body of the present invention uses a different approachcompared to the devices of U.S. Pat. No. 8,333,791 and WO 2009/045743.The devices of U.S. Pat. No. 8,333,791 and WO 2009/045743 are configuredto release pharmaceutical compounds in a surrounding area, while mountedon a spinal screw assembly. The deformable body of the present inventionis pressed with its bone contact surface against the periosteum, wherebythe shape of the bone contact surface is adapted to the actual surfaceprofile of the bone surface of the periosteum. The anaesthetic presentin the deformable body, and released from or through the bone contactsurface is directly administered at the desired location, i.e. thepunctured periosteum which typically is the origin of intense painexperienced by the patient. As a result, pain can be treated moredirectly and effectively. Furthermore, no or little anaesthetic willunintentionally diffuse into and/or have effect on tissue including thespinal cord, nerve roots and peripheral nerves in the near-field area.

Thereby, it is remarked that the devices of U.S. Pat. No. 8,333,791 andWO 2009/045743 are not typically configured to treat pain, and thereforethe location of these devices is of less importance compared to thespecific pain treatment objective of the deformable body of the presentinvention.

The deformable body of the invention may be applied in the living humanand/or animal body.

In an embodiment, the deformable body comprises a force applicationsurface to apply a force on the deformable body to press the bonecontact surface on the periosteum of a bone to be treated. The bonecontact surface may be arranged at a first side of the deformable bodyand force application surface may be arranged at a second side of thedeformable body, wherein the first side and the second side are oppositesides of the deformable body.

In an embodiment, the body may be bio-absorbable and/or biodegradable.

In an embodiment, the deformable body is a deformable ring-shaped bodyhaving an opening. This opening is one of the one or more through-goingopenings, for example a central opening in the ring-shaped body. Thesize of the opening has been selected such that the shank of a surgicalscrew element can be arranged through the ring-shaped body. The screwelement typically comprises a proximal part, for example a screw head,which has an increased diameter compared with the shank of the screwelement. The diameter of the opening of the deformable body may beselected to be smaller than the diameter of the proximal part of thescrew element. The screw element may be a complete screw or a partthereof. The screw element at least comprises a shank with screw threadand a proximal part having a larger diameter than the shank diameter.

The ring-shaped body may be arranged on the shank of the screw elementbefore the screw is screwed into a bone structure, for example a pedicleof a vertebra. When the screw element carrying the ring is screwed intoa bone, the ring-shaped body will be squeezed between the bone surfaceand the proximal part of the screw element. Due to this squeezing thedeformable ring-shaped body will be deformed, preferably elasticallydeformed, between the bone surface and the proximal part of the screwelement. As a result, the bone contact surface of the ring-shaped bodywill be firmly pressed against the bone surface, while the bone contactsurface adapts its shape to the shape of the bone surface.

The ring-shaped body may have any shape having an opening through whichthe shank of a screw element may extend. The outer surface of the ringextending around the opening may be circular, but also oval, polygonal,such as triangular, square, pentagonal with respect to a longitudinalaxis of the opening. The cross section of ring may also be of anysuitable shape, such as circular, oval, and polygonal. In an embodiment,the ring-shaped element has a donut like shape.

It is remarked that in an alternative embodiment, the deformable bodymay be a disc shaped body having a central thin part, for example amembrane, or, conversely, a protruding part that can be pierced by ascrew element to form an opening.

In an embodiment, the deformable body comprises a holding element orholding means, such as a lip, rim, bulge, or clip to hold the deformablebody on the shank of a screw element and/or to connect the deformablebody with a plate element, in an aligned position with a plate openingin the plate element. In an alternative embodiment, the deformable bodymay be glued on a plate element in an aligned position with the plateopening.

In an embodiment, the deformable body may have any shape suitable to beimplanted at a desired location.

In an embodiment, the bone contact surface is pervious for theanaesthetic to be released. For example, the bone contact surface is aporous or permeable surface through which the anaesthetic is released.The bone contact surface may become pervious for the anaesthetic after apredetermined time after implantation of the deformable body. Forexample, the bone contact surface may have a water-soluble coating or acoating that dissolves when heated at body temperature.

The anaesthetic may be provided in the deformable body, for example asparticles provided with a coating that may dissolve in an aqueoussolution. When the bone contact surface is a pervious surface for theanaesthetic, the anaesthetic may leave the deformable body through thebone contact surface. Since the bone contact surface is intended to befirmly pressed against the bone surface, the anaesthetic will directlybe released on the bone surface.

In an embodiment, the anaesthetic is arranged in a compartment delimitedby the bone contact surface and a further compartment wall, wherein thefurther compartment wall is a substantially non-pervious wall such thatanaesthetic will mainly be released through the bone contact surface.

The anaesthetic may be held in a compartment that is delimited by thebone contact surface and the further compartment wall, whereby thefurther compartment wall is a substantially non-pervious wall for theanaesthetic, i.e. the further compartment wall does not allow theanaesthetic to pass the further compartment wall or allows substantiallyless anaesthetic to pass the further compartment wall in comparison withanaesthetic that passes during a same time period through the bonecontact surface. As a result, the anaesthetic will mainly be releasedfrom the deformable body through the bone contact surface. This furtherensures that the anaesthetic is directly released on the bone surfacenext to the location where the screw element is brought through theperiosteum of the bone.

Since the anaesthetic is mainly released directly at the desiredlocation, less anaesthetic will have effect in tissue in the surroundingarea, i.e. in areas where no pain relief by anaesthetics is desired.Also, since substantially all anaesthetic is used at the location ofinterest, no additional anaesthetic has to be released in order tocompensate anaesthetic that will not be used at the desired location oftreatment. It is remarked that some pain relief may be desired in thedamaged skin and muscles, but this can be achieved with regular, lowdose painkillers.

Although the deformable body is designed for release at a specific sideof the compartment of the deformable body, for example at the bonecontact surface, the characteristics of the compartment walls, such asthe bone contact surface and the further compartment wall may, afterimplantation, change over time due to degradation of the deformablebody, for example since the deformable body is biodegradable orbioabsorbable. This means that the difference in perviousness of thebone contact surface and the further compartment wall may substantiallychange over time, after implantation, due to degradation of thedeformable body.

In an embodiment, the bone contact surface has a first permeability forthe anaesthetic to be released and wherein the further compartment wallhas a second permeability for the anaesthetic to be released, whereinthe first permeability is larger than the second permeability. In anembodiment, the further compartment wall may be impermeable for theanaesthetic to be released

In an embodiment, the anaesthetic is arranged in a compartment delimitedby the bone contact surface and a further compartment wall, wherein thebone contact surface has a first release rate for the anaesthetic to bereleased and wherein the further compartment wall has a second releaserate for the anaesthetic to be released, wherein the first release rateis larger than the second release rate. The first release rate andsecond release rate are defined as the quantities of anaesthetic thatare released per cm² surface area, during a same period, through thebone contact surface and through the further compartment wall,respectively.

Preferably, the first release rate is at least 2 times larger than thesecond release rate, more preferably at least 5 times larger than thesecond release rate, even more preferably at least 10 times larger thanthe second release rate.

The further compartment wall may be formed by the same material as theinner side of the compartment, but may for example be specificallytreated, for example by cross linking to adapt the release properties ofthe further compartment wall.

The further compartment wall may also be provided by a layer provided onor in the deformable body, for example a coating which is substantiallyimpermeable for the anaesthetic.

In an embodiment, the further compartment wall is an outer wall of thedeformable body. In this embodiment, the complete deformable body formsa compartment delimited by an outer wall of the deformable body. Fromthis compartment, only or at least mainly the bone contact surface willallow the release of anaesthetic from the deformable body. The furtherouter wall of the deformable body is preferably made non-pervious, forexample impermeable for the anaesthetic.

In an embodiment, both mechanical robustness and directional release maybe provided by an external shell arranged at least partially on thedeformable body. This shell can be constructed from the same material asthe anaesthetic containing interior of the deformable body of the devicewith altered mechanical and chemical properties, for example more densecrosslinking, or an alternative method of crosslinking. Alternatively,the shell can be constructed from a different polymer, for example asynthetic polymer such as polylactic-co-glycolic acid (PLGA),polycaprolactone (PCL) or polyvinyl alcohol (PVA), or a biopolymer suchas hyaluronic acid, chitosan, alginate, collagen or gelatin. Thesepolymers can be functionalized with a variety of chemical groups tomodulate their characteristics.

The external shell may provide a robust housing for theanaesthetic-containing interior of the deformable body and may bear mostof the mechanical strain/load during insertion of the deformable body.As the permeability and porosity of the shell can be adjusted, therelease can be directed towards a desired location, i.e. the bonecontact surface. This contact surface, with which the deformable body isarranged on the periosteum, may not be covered with the external shellto provide an opportunity for diffusion of the anaesthetic anddegradation of the interior of the deformable body. In an alternativeembodiment, the side of the deformable body comprising the bone contactsurface may also be covered with the external shell but this part of theshell may have an increased porosity and permeability for theanaesthetic compared to the other parts of the external shell. This canfor example be achieved with macroscopic or microscopic pores. Tocontrol the ratio between anaesthetic diffusion towards the bone contactsurface and diffusion towards the other surfaces, the porosity of thepart of the shell that encapsulates the other surfaces of the device canbe adjusted with either microscopic and/or macroscopic pores or othermeans to alter permeability.

The shell is flexible to adapt its shape to the bone surface on which itis pressed. The shell may be biodegradable, with the degradation timefor example being similar or slightly surpassing the degradation time ofthe drug-containing interior of the deformable body.

In an embodiment, the deformable body comprises a second compartment atleast partially delimited by a release surface, wherein the secondcompartment comprises a second pharmaceutical or biological compound,and wherein the release surface is pervious for the secondpharmaceutical or biological compound. In this embodiment, thedeformable body comprises two compartments, for example separated by asubstantially non-pervious separation wall provided between the firstcompartment and the second compartment.

As described above, the first compartment comprises an anaesthetic thatmay be released through the bone contact surface directly on the bonesurface, where treatment of pain is desired. The second compartment maycomprise a second pharmaceutical or biological compound that may bereleased through the release surface pervious for the secondpharmaceutical or biological compound. The pervious release surface ofthe second compartment may be arranged in such way as to not be pressedagainst the bone surface, when the deformable body is squeezed betweenthe bone surface and the proximal part of the screw element. The secondpharmaceutical or biological compound will therefore be released at adistance from the bone surface, and be further distributed within thearea in which the screw element is placed. The second compartment mayfor example be used to release antibiotics or analgesics in thesurrounding soft-tissue area of the bone-screw assembly.

Additionally, or alternatively, the deformable body may comprise afurther compartment at least partially delimited by a further releasesurface, wherein the further compartment comprises a furtherpharmaceutical or biological compound, and wherein the further releasesurface is pervious for the further pharmaceutical or biologicalcompound, wherein the release surface is arranged to be pressed togetherwith the bone contact surface against a periosteum of an outer bonesurface of a bone to be treated. In this embodiment, the deformable bodycan be used to release in addition to the anaesthetic, a furtherpharmaceutical or biological compound directly on the periosteum of anouter bone surface on which the deformable body is pressed. The furtherpharmaceutical or biological compound is for example a bone cancer drugor a regenerative drug.

The advantage of such further compartment is that the release profile ofthe anaesthetic and the release profile of the further pharmaceutical orbiological compound can each be optimized for the anaesthetic and therespective pharmaceutical or biological compound.

In an alternative embodiment, a further pharmaceutical or biologicalcompound may be provided in the same material/compartment as theanaesthetic, such that the further pharmaceutical or biological compoundmay be released together with the bone contact surface through or fromthe bone contact surface.

In an embodiment, a side of the deformable body comprising the bonecontact surface is flattened. To improve the contact surface between thebone contact surface and a relatively flat bone surface, the bonecontact surface may be provided as a flattened surface, when compared toa more circular cross-section.

In an alternative embodiment, the shape of the bone contact surface, innon-deformed state, may be adapted to a typical shape of a bone surfaceagainst which the deformable body will be pressed during use. Thisallows the bone contact surface to be more easily be brought intointimate contact with the bone surface to be treated.

In an embodiment, the deformable body comprises one or more deformationindicators that indicate a deformation, in particular a degree ofdeformation of the deformable body. In order to obtain, during use, anintimate contact between the bone contact surface and the bone surface,it is of importance that the deformable body is properly pressed againstthe bone surface so that the deformable body is deformed to adapt theshape of the bone contact surface to the shape of the bone surface onwhich it is placed. To confirm that the deformable body is sufficientlydeformed, the deformable body is provided with one or more deformationindicators that indicate a degree of deformation of the element.

The one or more deformation indicators may for example comprise one ormore markers that move upon deformation of the deformable body, whereinthis movement is detectable by a user.

In a ring-shaped embodiment of the deformable body, the one or moredeformation indicators may comprise one or more markers that arearranged to move outwards in a radial direction upon deformation of thedeformable body. The one or more markers may be arranged at one or morelocations which are, when the deformable body is arranged on the shankof the screw element, seen in longitudinal/axial direction of the screwelement concealed behind the proximal part of the screw element. Upondeformation of the deformable body, when being squeezed between theproximal part of the screw element and the bone surface, the one or moremarkers may move in radial direction to a location where the one or moremarkers are no longer concealed behind the proximal part of the screwelement, when seen in longitudinal/axial direction of the screw element.Thus, when the one or more markers are visible, it can be concluded thatthe deformable body has been substantially deformed, and as aconsequence, the bone contact surface is sufficiently pressed againstthe bone surface.

In an embodiment, the deformable body is at least partially radiopaqueand/or the deformable body comprises one or more radiopaque elements. Tomake the deformable body at least partially radiopaque, the outer wallor shell of the deformable body may be impregnated with a radiopaquematerial or a radiopaque coating may be provided over at least a part ofthe outer surface of the deformable body. The one or more radiopaqueelements may for example be particles that are arranged on the outersurface of deformable body and/or at least partially embedded in thedeformable body. The one or more radiopaque elements facilitate thedetectability of the deformable body using fluoroscopy, X-ray or CTtechniques.

In addition, or as an alternative, the deformable body comprisesmaterials that can be visualized by ultrasound techniques.

In an embodiment, the deformable body comprises one or more markingsindicating a location of the bone contact surface. In order for thedeformable body to be used properly, a marking may be provided thatindicates directly or indirectly the location of the bone contactsurface such that it can easily be checked that the bone contact surfaceis arranged or will be arranged against the bone surface.

The marking may for example be a line, sign and/or colour indicating thelocation of the bone contact surface, but may also be a marking thatindicates the orientation with which the deformable body should bearranged on a bone surface. It will be clear that the latter markingalso indirectly indicates the location of the bone contact surface.

It is remarked that other markings may be provided to indicate otherrelevant details of the deformable body, for example one or more of ananaesthetic dose, an anaesthetic release profile, a size, a dose ofsecond pharmaceutical or biological compound, a second or biologicalpharmaceutical compound release profile, etc.

In an embodiment, the deformable body is made of a visco-elasticmaterial, a degradable felt material, a sponge-like material, a gelatinmaterial, a gel, in particular a hydrogel, a polymer or any combinationthereof. The deformable body may be made of any suitable material thatprovides a suitable deformation of the deformable body due to pressingthe deformable body on the periosteum of an outer bone surface, forexample by squeezing the deformable body between a proximal part of ascrew element and the bone surface of the bone in which the screwelement is screwed.

Other examples of suitable material to form the deformable body arepolylactic-co-glycolic acid (PLGA), polycaprolactone (PCL), alginates,polymers, etc.

Since the deformable body is intended to be implanted in a living humanor animal body, the materials of the deformable body are preferablybiocompatible and/or biodegradable materials. The degradation of thematerial(s) of the deformable body may be in the range of 3 days-26weeks after implantation.

In an embodiment, the deformable body is freeze-dried. Freeze-drying thedeformable body may substantially increase the shelf-life of thedeformable body. Freeze-drying may also improve mechanical properties ofthe deformable body.

The invention also relates to a combination of the deformable body ofany of the claims 1-15 and a surgical screw element having a shank,wherein the deformable body is arranged on the shank of the surgicalscrew element.

The deformable body may for example be a ring-shaped element having anopening, for example a central opening. The diameter of the opening ofthe ring-shaped element may substantially correspond to the diameter ofthe shank of the surgical screw element. The diameter of the opening maybe slightly larger than the shank diameter so that the ring-shapedelement can easily be placed on the shank of the screw element. Thediameter of the opening may however also be slightly smaller than theshank diameter so that the ring-shaped element will clamp on the shankdue to the deformation required to fit the ring-shaped element on theshank of the screw element.

A holding element, such as a lip, rim, clip, screw thread etc. may beused to hold the deformable body on the shank of the screw element. Theholding element may be provided on the screw element and/or on thedeformable body.

The screw element further comprises a proximal part having a diameterwhich is larger than the diameter of the opening of the ring-shapedelement, for example a screw head or a connector, for instance toconnect further parts of a spinal fixation system. The proximal part maybe any part that is arranged proximal of the location of the ring-shapedelement on the shank of the screw element and has a diameter which islarger than the diameter of the opening of the ring-shaped element. Theproximal part may be integrally provided with the screw element, or maybe a separate part of the screw element, or a combination thereof. Theproximal part may also specifically be provided to squeeze thering-shaped element between the proximal part and the bone surface.

The screw element may be a standard screw element, i.e. not specificallyadapted for use in combination with the ring-shaped element. Thering-shaped element may be specifically designed to fit on the shank ofthe standard screw element, or possibly a range of standard screwelements.

In an alternative embodiment, the screw element may be specificallyadapted to be provided together with the ring-shaped element. Forexample, the shank of the screw element may be adapted to receive thering-shaped element. In such embodiment, the shank of the screw elementmay comprise a circumferential rim or circumferential detention thatmates with the ring-shaped element in order to hold the ring-shapedelement on the shank of the screw element.

The present invention further relates to bupivicaine, liposomebupivacaine, lidocaine or levobupivacaine for use in a method oftreating pain, in particular pain caused by placing a surgical screwelement through periosteum of a bone of a patient,

wherein the bupivicaine, liposome bupivacaine, lidocaine orlevobupivacaine is administered by a deformable body as claimed in anyof the claims 1-19.

The present invention furthermore relates to a method of treating pain,in particular pain caused by placing a surgical screw element throughperiosteum of a bone of a patient, comprising the steps of:

placing a deformable body on a shank of the surgical screw element,wherein the deformable body comprises a bone contact surface to bepressed against bone surface upon screwing of the screw element in abone, and wherein the deformable body comprises an anaesthetic that isreleased from or through the bone contact surface.

screwing the surgical screw element into the bone of the patient,whereby the deformable body is squeezed between the bone surface and aproximal part of the screw element to press the bone contact surfaceagainst bone surface, and

releasing the anaesthetic from or through the bone contact surface.

It is remarked that according to the present invention, the deformablebody comprises an anaesthetic. In alternative embodiments, thedeformable body may comprise, in addition to or as an alternative, otherpharmaceutical or biological compounds.

The term “pharmaceutical or biological compound”, as used herein, refersto any substance used internally as a medicine/drug for the treatment,cure, or prevention of a disease or disorder. Examples of pharmaceuticalor biological compounds that can be administered using the deformablebody of the present invention are for example anaesthetics, antibiotics,bone growth stimulating agents, analgesics, chemotherapeutic agents,steroids (including retinoids), hormones, anti-microbials, antivirals,anti-inflammatory compounds, radiation absorbers, includingUV-absorbers, vaccins, and stemcells.

The active pharmaceutical compound is included in the composition in anamount sufficient to deliver to the host patient an effective amount toachieve a desired effect. The amount of drug or biologically activeagent incorporated into the composition depends upon the desired releaseprofile, the concentration of drug required for a biological effect, andthe desired period of release of the drug.

Embodiments of the invention will now be described, by way of exampleonly, with reference to the accompanying schematic drawings in whichcorresponding reference symbols indicate corresponding parts, and inwhich:

FIG. 1 shows a top view of a ring-shaped element according to anembodiment of the invention;

FIG. 2 shows a cross-section A-A of the ring-shaped element of FIG. 1;

FIG. 3 shows a combination of a screw element and the ring-shapedelement of FIG. 1 arranged on the shank of the screw element;

FIG. 4 shows the combination of FIG. 3 screwed into a bone of a patient;

FIG. 5 shows an example of a release profile of the ring-shaped elementof FIG. 1;

FIG. 6 shows a first alternative embodiment of a ring-shaped elementaccording to the invention;

FIGS. 7 and 8 show a second alternative embodiment of a ring-shapedelement according to the invention; and

FIG. 9 shows a third alternative embodiment of a ring-shaped elementaccording to the invention in combination with a specifically designedscrew element;

FIG. 10 shows an alternative embodiment of a deformable body accordingto the invention;

FIG. 11 shows a cross-section B-B of the deformable body of FIG. 10;

FIG. 12 shows a cross-section of a plate in combination with ring shapedelements according to an embodiment of the invention;

FIG. 13 shows a cross-section of a fourth alternative embodiment of aring-shaped element according to the invention;

FIG. 14 shows a cross-section of a fifth alternative embodiment of aring-shaped element according to the invention;

FIGS. 15a, 15b and 15c show a method to arrange a ring-shaped element ona shank of a screw element as shown in FIG. 3; and

FIG. 16 shows a further combination of a screw element and a ring-shapedelement according to an embodiment of the invention.

FIG. 1 shows a top view of a deformable body according to an embodimentof the invention in the form of a ring-shaped element, generally denotedby reference numeral 1. The ring-shaped element 1 comprises a deformablering body 2 having a central opening 3. The ring-shaped element 1 isdesigned to be placed on a shank of a surgical screw element, forexample a pedicle screw of a spinal fixation system.

The ring body 2 is made of a deformable biocompatible material, forexample gelatin material. The ring-shaped element 1 is preferablybio-absorbable.

FIG. 2 shows a cross-section A-A of the ring-shaped element 1. The outersurface wall of the ring-shaped element 1 is formed by a bone contactsurface 4 and a compartment wall 5. The bone contact surface 4 and thecompartment wall 5 delimit a compartment 6. The compartment 6, basicallyformed by the ring body 2 contains bupivacaine. The bone contact surface4 is provided to be pressed on the periosteum of a bone to be treated.The bone contact surface 4 has, after implantation, a first release ratefor the anaesthetic to be released and the compartment wall 5 has asecond release rate for the anaesthetic to be released. The firstrelease rate is substantially larger than the second release rate, forexample at least 2, preferably at least 10 times the second releaserate. As a result, the bupivacaine will be released from the compartment6 mainly through the bone contact surface 4 according to a desiredrelease profile over time.

The bone contact surface 4 to be pressed on the periosteum of a bone isarranged at a first side of the ring-shaped element. At a second side ofthe ring-shaped element 1, opposite to the first side, a forceapplication surface 12 is provided. The force application surface 12 isarranged to apply a force on the ring-shaped element 12 to press thering-shaped element 12 on the periosteum.

FIG. 3 shows a combination of a surgical screw element 20 and thering-shaped element 1 of FIG. 1 mounted on a shank 21 of the screwelement 20. The shank 21 comprises a screw thread 22 to screw the screwelement 20 into bore provided in a bone of a patient. The screw element20 further comprises a proximal part 23 having a screw head 24 integralwith the shank 21 and a separate connector part 25. It is remarked thatthe screw element 20 is a standard screw element, i.e. not specificallyadapted for use in combination with the ring-shaped element 1. The screwelement 20 is for example a screw element of the spinal fixation systemdisclosed in US 2010/031228.

The diameter of the central opening 3 of the ring-shaped element 1substantially corresponds to the diameter of the shank 21, such that theshank 21 can be moved through the ring-shaped element 1 to the positionshown in FIG. 3. In this position of the ring-shaped element 1, thering-shaped element 1 cannot be moved further in the proximal directionof the shank 21 as the proximal part 23 of the screw element 20 preventssuch movement, since the diameter of the proximal part 23 issubstantially larger than the diameter of the central opening 3.

The outer diameter of the ring-shaped element 1 may, for example, be inthe range of 1 mm to 40 mm, preferably in the range of 5 mm to 25 mm.The diameter of the central opening 3 may for example be in the range0.25 mm to 20 mm, preferably in the range of 2 mm to 15 mm.

FIG. 4 shows the combination of the surgical screw element 20 and thering-shaped element 1 after it has been screwed into a bore 50 providedin a bone 51 of a patient to be treated. The bone 51 is for example apedicle of a spine of a patient.

It can be seen that the ring-shaped element 1 is squeezed between theproximal part 23 of the screw element 20 and bone surface 52 of the bone51. As a result of this squeezing, the ring body 2 is deformed resultingin an intimate contact between the bone contact surface 4 and the bonesurface 52. Due to this intimate contact, the bupivacaine that isreleased from the compartment 6 through the bone contact surface 4 (asindicated by arrows) will be directly administered to the periosteumwhich is damaged due to the introduction of the screw element 20. Thus,the ring-shaped element 1 allows to directly administer locally apharmaceutical compound, in particular bupivacaine to relief the painthat the patient experiences due to the damage of the periosteum. Sincethe compartment wall 5 of the ring-shaped element 1 has a relatively lowpermeability for the bupivacaine, the bupivacaine will mainly bereleased through the bone contact surface which is in direct contactwith the bone to be treated. This allows for a very specific localdelivery of the bupivacaine, which is generally desirable. Also, sincethe bupivacaine is released directly at this specific location, no orlittle bupivacaine will be spilled in tissue in the surrounding area,i.e. in areas where no pain relief is desired. This allows foradministration of a more precise amount of bupivacaine during apredetermined timeperiod and at the desired location and also preventsside effects of the release of bupivacaine.

The deformability of the ring body 2 is designed such that the shape ofthe bone contact surface 4 adapts to the bone surface 52 on which it ispressed. This means that the bone contact surface 4 will followirregularities of the bone surface. In practice, the consistency anddeformability of the ring body 2 may be similar to a wine gum.

The bone contact surface 4 of the ring-shaped element 1 shown in FIGS.1-4 is relatively flat and therefore in particular suitable for bonesurfaces that are mainly flat. Generally, it is possible to adapt theshape of the deformable body and its bone contact surface 4 to othertypical shapes of skeletal bones and implants at the location wherescrew elements are introduced into the bone in accordance with typicalsurgical procedures including, but not limited to, (plate-) fixation of:long bones, the pelvis, ribs, the shoulder girdle, large joints of thehip and knee and ankle, elbow, wrist, hand and foot, dental implants andcranial/maxillar/mandibular osteosynthesis instrumentations.

The bupivacaine is released according to a desired release profile overtime.

FIG. 5 shows an example of such release profile. In FIG. 5, thehorizontal axis indicates time T in hours and the vertical axisindicates the amount of bupivacaine R that is released from thering-shaped element 1 through the bone contact surface 4.

Directly after implantation of the screw element 20 a high level of painis experienced by a patient in which the screw element is placed 20. Tocounteract this pain a peak of bupivacaine release is realized asquickly as possible in the first twelve hours after implantation.Thereafter, the bupivacaine release is maintained at a desired leveluntil approximately 48-72 hours after implantation. Thereafter, thebupivacaine release may slowly decrease to zero.

Any other desirable release profile may also be designed usingbupivacaine or another anaesthetic or combination of anaesthetics.

FIG. 6 shows a first alternative embodiment of a ring-shaped element 1according to the invention. In the ring-shaped element 1 of FIG. 6 afirst compartment 6 containing bupivacaine and a second compartment 7containing a second pharmaceutical compound, for example antibiotics,are provided. The first compartment 6 and the second compartment 7 areseparated from each other by a separation wall 8.

The first compartment 6 is partly delimited by the bone contact surface4 that will be pressed during use against a bone surface 52 to betreated. The bone contact surface has a relatively high permeability forbupivacaine. The other walls delimiting the first compartment 6 have arelatively low permeability for bupivacaine, i.e. do not allowbupivacaine to pass the respective walls, or only allow a relatively lowquantity of bupivacaine to pass the respective walls.

The second compartment is partly delimited by a release surface 9 havinga relatively high permeability for the second pharmaceutical compound.The other walls delimiting the second compartment 6 have a relativelylow permeability for the second pharmaceutical compound, i.e. do notallow the second pharmaceutical compound contained in the secondcompartment 7 to pass through these other walls, or only allow arelatively low quantity of the second pharmaceutical compound to passthrough these other walls.

The release surface 9 will typically not be pressed against the bonesurface 52, when the ring-shaped element 1 is squeezed between the bonesurface 52 and the proximal part 23 of the screw element 20. As aresult, the second pharmaceutical compound will be released at alocation spaced from the bone surface 52, and the second pharmaceuticalcompound will be more distributed over the area in which the screwelement is placed. The second compartment 7 of the ring-shaped element 1may therefore typically be used to create such locally more distributedrelease of a pharmaceutical compound, for example antibiotics.

FIG. 7 shows a second alternative embodiment of a ring-shaped element 1.The ring-shaped element 1 of FIG. 7 comprises four deformationindicators, in the form of four markers 10 that indicate a degree ofdeformation of the ring-shaped element 1. The four markers 10 arearranged on a top surface of the ring-shaped element 1 distributed overthe circumference of the ring-shaped element 1. When seen inlongitudinal direction of a screw element 20 arranged through thering-shaped element 1 the four markers are concealed behind the proximalpart 23 (shown in dashed line) of the screw element 20.

To obtain an intimate contact between the bone contact surface 4 and thebone surface 52, the ring body 2 is deformed to adapt the shape of thebone contact surface 4 to the bone surface 52 on which it is placed.

The markers 10 are each arranged at a respective location that movesradially outwards when the ring body 2 is deformed due to squeezingbetween the bone surface 52 and the proximal part 23 of the screwelement 20. As a result of this radially outwards movement of themarkers 10 when the ring body is deformed, the markers 10 are no longerconcealed by the proximal part 23 of the screw element 20 as shown inFIG. 7.

Since the four markers 10 are visible in the deformed state of thering-shaped element 1 shown in FIG. 7, it can be concluded that, in thisdeformed state, the ring body 2 has been sufficiently deformed to createan intimate contact between the bone contact surface 4 of thering-shaped element 1 and the bone surface 52. As such the markers 10are suitable deformation indicators that advantageously can be used toconfirm sufficient deformation of the ring body during placement of ascrew element 20 in a bone of a patient.

FIG. 9 shows a third alternative embodiment of a combination of aring-shaped element 1 and a surgical screw element 20. The surgicalscrew element 20 comprises a shank 21 and a proximal part 23 formed byscrew head 24. The ring-shaped element 1 is arranged on the shank 21 ofthe surgical screw element 20.

The screw element 20 and the ring-shaped element 1 are specificallydesigned to be used in combination. The shank 21 comprises acircumferential rim 26 that is configured to hold the ring-shapedelement 1 on the shank 21. The diameter of the central opening 3 of thering-shaped element 1 is adapted to the diameter of the shank 21 and theheight of the inner wall of the ring-shaped element 1 is adapted to thedistance between the proximal part 23 and the circumferential rim 23.

The ring-shaped element 1 comprises a relatively small top area and alarge bottom area. The top area is configured to substantiallycorrespond with the distal surface area of the proximal part 23 so that,when the ring-shaped element 1 is squeezed between the proximal part 23and the bone surface 52, the complete top area of the ring-shapedelement 1 is pressed downwards by the proximal part 23.

The relatively large bottom area comprises the bone contact surface 4which may therefore also be relatively large. This has the advantagethat there is a relatively large surface that can be brought intocontact with the bone surface 52 and through which an anaesthetic can bereleased to the bone surface 52.

FIG. 10 shows an alternative embodiment of a deformable body 30according to the invention. FIG. 11 shows a cross-section B-B of thedeformable body 30 of FIG. 10. The deformable body 30 comprises a bonecontact surface 31 to be pressed against a bone surface of a bone, acircumferential side wall 32 and a top wall 33 opposite to the bonecontact surface 31. The deformable body 30 contains an anaesthetic. Thebone contact surface 31 is pervious for the anaesthetic such that, afterimplantation, the anaesthetic may be released through the bone contactsurface 31. The circumferential side wall 32 and the top wall 33 of thedeformable body 30 are not pervious for the anaesthetic such that theanaesthetic will be mainly, preferably only released through the bonecontact surface 31.

The anaesthetic is arranged in the deformable body in a form that itwill be released according to a predetermined controlled releaseprofile.

The deformable body 30 is provided with four fixation locations 34 eachcomprising two aligned recesses 35 at opposite sides of the deformablebody such that a thin part 36 is formed between each set of two recesses35. The thin parts 36 may be pierced, for example by screw elements orseparate piercing element to create through-going openings through therecesses 35. Each of these through-going openings may be used toaccommodate the shank of a respective screw element to press thedeformable body 30 against a bone surface. The screw elements may forexample also be used to press a plate on the deformable body 30 in orderto press the deformable body 30 against a bone surface. The plate mayadvantageously be provided with a pattern of through-going openingscorresponding to the pattern of fixation locations of the deformablebody 30. The plate may be provided with a lip, rim, or clip to hold thedeformable body on the plate to facilitate placement of plate anddeformable body 30.

It is remarked that the through-going openings created by piercing thethin parts 36 may also be used to arrange alternative fixation elementstherethrough, such as wires or bands with which the bone contact surface31 can be pressed against the bone surface in order to adapt the shapeof the bone contact surface 31 to the shape of the bone surface on whichthe deformable body 30 is pressed. It will be clear for the man skilledin the art that many modifications may be made to adapt the deformablebody, the ring-shaped element and/or the screw element to specificcircumstances of the location where the deformable body and/or thecombination of screw element and ring-shaped element is applied.

FIG. 12 shows a cross section of a plate element 60 with two ring-shapedelements 1 used in combination with the plate element 60. When thering-shaped elements 1 are used in combination with the plate element60, the ring-shaped elements 1 cannot be pre-arranged on the shank ofthe respective screw elements with which the plate element 60 will bemounted on a bone, since the ring-shaped elements 1 cannot be movedthrough the plate openings 61 provided in the plate element 60.Furthermore, it may be difficult to align a ring-shaped element 1between the plate element 60 and an outer bone surface of a bone onwhich the plate element 60 is mounted once the plate element 60 isarranged in its intended location, for example when one screw element isscrewed into a bone.

Therefore clips 62 are provided that hold the ring-shaped elements 1aligned with the plate openings 61 and connected with the plate element60, such that the ring-shaped elements 1 in combination with the plateelement 60 may be arranged on a bone surface on which the plate element60 may be mounted. The clips 62 will ensure that the ring-shapedelements 1 will remain aligned with the plate openings 61.

When a screw element 20 is arranged in the openings, the clips 62 are nolonger required since the screw element 20 will keep the respectivering-shaped element 1 at the desired location, and the clips 62 may,when desired, be removed.

The clips 62 may be designed such that the clips 62 can be removed bypulling the clips 62 out of the plate openings 61 when the screwelements 20 are placed in the plate openings 61. The clips 62 may alsobe made of a material than can be broken or flexed by the screw element20 such that the clips 62 do not prevent or hinder the placement of thescrew element 20 through the plate openings 61 and the ring-shapedelements 1. It is also possible that the clips 62 are not removed, forexample when the clips do not prevent placement of the screw element 20and/or when the clips 62 are made of bio absorbable material.

In alternative embodiments, other means or devices may be provided toconnect the ring-shaped elements 1 to the plate element 60 in an alignedposition with respect to the plate openings 61. For example, thering-shaped elements 1 may be glued to the plate element 60, or otherfeatures such as rims or bumps, matching the diameter of holes in aplate, may be provided to at least temporarily connect the ring-shapedelements 1 to the plate element 60. The ring-shaped element may also beheld by clips or other elements that are not arranged in plate openingsthrough which the fixation elements are placed but at other locations,such as other openings or an edge of the plate.

FIG. 13 shows a fourth alternative embodiment of a ring-shaped elementaccording to the invention. The ring-shaped element 1 of FIG. 13comprises an outer shell 70 that functions as the further compartmentwall which is less pervious for the anaesthetic in the deformable bodycompared to the perviousness of the bone contact surface. The outershell provides both mechanical robustness and directional release, i.e.release of the anaesthetic at the bone contact surface 4.

The shell 70 can be constructed from the same material as theanaesthetic containing interior of the deformable body, with alteredmechanical and chemical properties, for example comprising more densecrosslinking or by an alternative method of crosslinking that results ina more stiff and non-pervious material. Alternatively, the shell 70 canbe constructed from a different material, for example a polymermaterial. The polymer material is for example a synthetic polymer suchas polylactic-co-glycolic acid (PLGA), polycaprolactone (PCL) orpolyvinyl alcohol (PVA), or a biopolymer such as hyaluronic acid,chitosan, alginate, collagen or gelatin. These polymers can befunctionalized with a variety of chemical groups to precisely modulatetheir characteristics.

The shell 70 provides a robust housing for the anaesthetic containinginterior of the deformable body and can bear most of the mechanicalstrain/loads during insertion. As the permeability and porosity of theshell 70 can be adjusted, the release of the anaesthetic can be directedtowards the desired location, typically the bone contact surface. Thisbone contact surface, with which the deformable body is placed onperiosteum and bone, is not covered with the external shell 70 toprovide an opportunity for diffusion of the drug and degradation of theinner part of the device.

In an alternative embodiment, the bone contact surface may be coveredwith the shell 70 but this part of the shell 70 has an increasedporosity and permeability for the anaesthetic compared to the otherparts of the external shell 70. This can be for example be achieved withmacroscopic or microscopic pores. To control the ratio betweenanaesthetic diffusion towards the bone contact surface of the deformablebody and diffusion towards the compartment wall, the porosity of thepart of the shell that encapsulates the non-bone contact surfaces of thedevice can be adjusted via either micro- or macroscopic pores or othermeans of altering permeability.

The shell 70 is constructed to be flexible to adapt its shape to thebone contour on which it is implanted. The shell 70 may bebiodegradable, with the degradation time ideally being similar orslightly surpassing the degradation time of the inner, drug-containingpart of the device.

FIG. 14 shows an embodiment of a ring-shaped element 1 for percutaneousplacement of a screw element 20 into a bone. To facilitate safeplacement of deformable body and screw element 20 through the skin of apatient, the shape of the outer surface of the ring-shaped element 1 isconical wherein the diameter of the outer surface in proximal direction,i.e. away from the bone contact surface 4, increases.

Further, the maximal diameter of the ring-shaped element 1 issubstantially the same as the diameter of the screw head 24. The maximumdiameter of the ring-shaped element 1 may also be smaller than thediameter of the screw head 24.

The advantage of the conically increasing diameter of the outer surfaceof the ring-shaped element 1 and that the maximal diameter of thering-shaped element 1 substantially corresponds with the diameter of thescrew head 24 is that the ring-shaped element 1 may relatively easily bepushed through skin and underlying soft tissue until it is pressedagainst the periosteum of the bone in which the screw element 20 isplaced. Thereby, there is less risk of damaging the ring-shaped element1.

To protect the material of the ring-shaped element 1, the material ofthe deformable body may, at least partially, for example the outersurface, be made relatively strong.

FIGS. 15a, 15b and 15c show a method to mount a ring-shaped element 1 ona shank 21 of a screw element 20. The method provides a relatively easyand reliable manner to arrange the ring-shaped element 1 on a screwelement 20. The method may also protect the relatively soft material ofthe ring-shaped element 1, and does not require direct manual contactwith the hands of a person handling the ring shaped-element 1.

In FIG. 15a , the ring-shaped element 1 is shown before being mounted onthe shank 21 of the screw element 20. The ring-shaped element 1 isarranged on one end of a sleeve 80. The sleeve 80 may be made ofrelatively strong material that is not easily damaged by the screwthread 22. The ring-shaped element 1 may be arranged during productionon the sleeve 80 or this may be done just for mounting of thering-shaped element 1 on the screw element 20. When the ring-shapedelement 1 is arranged on the sleeve 80, the sleeve will also facilitateplacement of the ring-shaped element 1 in the correct orientation on thescrew element 20, i.e. with the bone contact surface 4 facing the distalend of the screw element 20.

On the sleeve 80, a pusher element 81 is arranged. The pusher element 81is provided to push, as explained hereinafter, the ring-shaped element 1from the sleeve 80. The pusher element 81 can slide over the outersurface of the sleeve 80.

In FIG. 15b , the screw element 20 is moved into the sleeve 80, asindicated by arrow 82. The ring-shaped element 1 is now properly alignedwith the location where the ring-shaped element 1 should be arranged onthe shank 21 of the screw element 20. Since the shank 21 and its screwthread 22 are moved through the interior of the sleeve 80, thering-shaped element 1, which is arranged on the outer surface of thesleeve 80 cannot be damaged by the screw thread.

From the position in FIG. 15b , the sleeve 80 can be pulled from theshank 21 of the screw element 20, while the ring-shaped element 1 isheld in its relative position with respect to the screw element 20, forexample by pushing the pusher element 81 against the ring-shaped element1. As a result, the pusher element 81 will push the ring-shaped element1 from the sleeve into the position shown in FIG. 15c . Once thering-shaped element 1 is arranged in its desired position with respectto the shank 21 of the screw element 20, as shown in FIG. 15c , thesleeve 80 and the pusher element 81 may be removed from the shank 21.

The sleeve 80 shown in FIGS. 15a, 15b and 15c is a stiff sleeve. In analternative embodiment, the sleeve may be more flexible.

Before use, the ring-shaped element 1 and the sleeve 80 may be connectedto each other, for example by a tear line or cut line that is torn orcut after the ring-shaped element 1 is arranged at the desired locationon the shank 21 of the screw element 20. The tear line or cut line maybe provided between the ring-shaped element 1 and the sleeve 80, or inthe sleeve 80 itself.

In another embodiment of the ring-shaped element, the inner surface ofthe ring-shaped element, i.e. the surface facing towards thelongitudinal axis may be provided with a layer of relatively strongmaterial, such as for example shown in FIG. 14, to protect thering-shaped element 1 when it is moved over the shank 21 of the screwelement 20.

FIG. 16 shows an embodiment of a ring-shaped element 1 in combinationwith a screw element 20. The screw element 20 comprises a conical shankpart 27 having a conical outer surface 28 mating with a conical innersurface 11 of the ring-shaped element 1. The angle of conical outersurface 28 and the conical inner surface with respect to thelongitudinal axis of the screw element 20 and the ring-shaped element 1are substantially the same. When the screw element 20 is screwed into abone and the bone contact surface will be pushed against the periosteumof the bone, the ring will not only be pressed in axial direction butalso in radial direction. This may have the advantage that thering-shaped element 1 may be applied over a larger insertion range ofthe screw element 20 without exerting a too large, radially-directed,force on the material of the ring-shaped element 1.

1-21. (canceled)
 22. A deformable body, wherein the deformable bodycomprises a bone contact surface to be pressed against periosteum of abone surface of a bone such that the bone contact surface adapts itsshape to the shape of the bone surface, wherein the deformable bodycomprises one or more through-going openings arranged to receive afixation element which is used to press the deformable body against thebone surface, wherein the deformable body comprises an anaesthetic thatis to be released from or through the bone contact surface, and whereinthe anaesthetic is arranged in a compartment delimited by the bonecontact surface and a further compartment wall, wherein the bone contactsurface has a first release rate for the anaesthetic to be released andwherein the further compartment wall has a second release rate for theanaesthetic to be released, wherein the first release rate is largerthan the second release rate.
 23. The deformable body of claim 22,wherein the deformable body is a ring shaped body having an openingbeing one of the one or more through-going openings and through which ashank of a surgical screw element can be placed, wherein the bonecontact surface is to be pressed against bone surface by screwing of thescrew element in a bone while the deformable body is placed on the shankof the screw element.
 24. The deformable body of claim 22, wherein thebone contact surface is pervious for the anaesthetic to be released. 25.The deformable body of claim 22, wherein the anaesthetic is arranged ina compartment delimited by the bone contact surface and a furthercompartment wall, wherein the further compartment wall is asubstantially non-pervious wall for the anaesthetic such that theanaesthetic will mainly be released through the bone contact surface.26. The deformable body of claim 22, wherein the further compartmentwall is an outer wall of the deformable body.
 27. The deformable body ofclaim 22, wherein the deformable body comprises a second compartment atleast partially delimited by a release surface, wherein the secondcompartment comprises a second pharmaceutical or biological compound,and wherein the release surface is pervious for the secondpharmaceutical or biological compound.
 28. The deformable body of claim27, wherein the second pharmaceutical or biological compound comprisesan antibiotic, an analgesic, a bone growth stimulating agent, stem cellsand/or a chemotherapeutic agent.
 29. The deformable body of claim 22,wherein the deformable body comprises one or more deformation indicatorsthat are arranged indicate a deformation of the deformable body.
 30. Thedeformable body of claim 22, wherein the one or more deformationindicators comprise one or more markers that are arranged to move upondeformation of the deformable body.
 31. The deformable body of claim 22,wherein the anaesthetic is only or mainly to be released from or throughthe bone contact surface.
 32. The deformable body of claim 22, whereinthe anaesthetic comprises bupivacaine, liposome bupivacaine, lidocaineand/or levobupivacaine.
 33. The deformable body of claim 22, wherein thedeformable body comprises one or more indicators indicating a locationof the bone contact surface.
 34. The deformable body of claim 22,wherein the deformable body is made of a visco-elastic material, adegradable felt material, a sponge-like material, a gelatin material, agel, in particular a hydrogel, a polymer or any combination thereof. 35.The deformable body of claim 22, wherein the deformable body comprises aforce application surface to apply a force on the deformable body,wherein the bone contact surface is arranged at a first side of thedeformable body and the force application surface is arranged at asecond side of the deformable body, wherein the first side and thesecond side are opposite sides of the deformable body.
 36. A deformablebody, wherein the deformable body comprises a bone contact surface to bepressed against periosteum of a bone surface of a bone such that thebone contact surface adapts its shape to the shape of the bone surface,wherein the deformable body comprises one or more through-going openingsand/or one or more fixation locations arranged to receive a fixationelement, and wherein the deformable body comprises an anaesthetic thatis released from or through the bone contact surface.
 37. The deformablebody of claim 36, wherein the deformable body is a ring shaped bodyhaving an opening being one of the one or more through-going openingsand through which a shank of a surgical screw element can be placed,wherein the bone contact surface is to be pressed against bone surfaceby screwing of the screw element in a bone while the deformable body isplaced on the shank of the screw element.
 38. The deformable body ofclaim 36, wherein the bone contact surface is pervious for theanaesthetic to be released.
 39. The deformable body of claim 36, whereinthe anaesthetic is arranged in a compartment delimited by the bonecontact surface and a further compartment wall, wherein the furthercompartment wall is a substantially non-pervious wall for theanaesthetic such that the anaesthetic will mainly be released throughthe bone contact surface.
 40. The deformable body of claim 36, whereinthe deformable body comprises a second compartment at least partiallydelimited by a release surface, wherein the second compartment comprisesa second pharmaceutical or biological compound, and wherein the releasesurface is pervious for the second pharmaceutical or biologicalcompound.
 41. The deformable body of claim 36, wherein the secondpharmaceutical or biological compound comprises an antibiotic, ananalgesic, a bone growth stimulating agent, stem cells and/or achemotherapeutic agent.
 42. The deformable body of claim 36, wherein thedeformable body comprises one or more deformation indicators thatindicate a deformation of the deformable body.
 43. The deformable bodyof claim 36, wherein the one or more deformation indicators comprise oneor more markers that are arranged to move upon deformation of thedeformable body.
 44. The deformable body of claim 36, wherein theanaesthetic is only or mainly released from or through the bone contactsurface.
 45. The deformable body of claim 36, wherein the anaestheticcomprises bupivacaine, liposome bupivacaine, lidocaine and/orlevobupivacaine.
 46. The deformable body of claim 36, wherein thedeformable body comprises one or more indicators indicating a locationof the bone contact surface.
 47. The deformable body of claim 36,wherein the deformable body is made of a visco-elastic material, adegradable felt material, a sponge-like material, a gelatin material, agel, in particular a hydrogel, a polymer or any combination thereof. 48.The deformable body of claim 36, wherein the deformable body comprises aforce application surface to apply a force on the deformable body,wherein the bone contact surface is arranged at a first side of thedeformable body and the force application surface is arranged at asecond side of the deformable body, wherein the first side and thesecond side are opposite sides of the deformable body.
 49. A combinationof the deformable body of claim 36 and a surgical screw element having ashank, wherein the deformable body is arranged on the shank of thesurgical screw element.
 50. The combination of claim 49, wherein theshank comprises a circumferential rim or circumferential detention thatmates with the deformable body to hold deformable body on the shank. 51.The combination of claim 49, wherein the screw element is a pediclescrew for spinal treatment.
 52. A kit comprising: the deformable body ofclaim 36, a sleeve, wherein the sleeve can be arranged in the openingand wherein the sleeve comprises a channel to receive a shank of asurgical screw element, and wherein the sleeve is arranged to be slidover the shank of a screw element to position the deformable body on adesired position on the shank.
 53. The kit of claim 52, wherein the kitfurther comprises a pusher element to push the deformable body from thesleeve.